Electroluminescence (EL) devices are display devices that are composed of films containing organic compounds as an electroluminescent layer. In a more sophisticated, but common form, EL devices may include anode and cathode layers between which are disposed a hole transport layer, an electron transport layer, and an emissive layer that is disposed between the hole transport and electron transport layers.
Compounds in the various layers are generally classified as electroluminescent materials and/or charge transport materials. Several properties are required for such electroluminescent and charge transport compounds including high fluorescent quantum yield in solid state, sufficient mobility of electrons and holes, chemical stability during processing, and the ability to form morphologically stable films. These desired features increase the lifetime of an EL device. There is a continual need for improved electroluminescent compounds and films containing the same.
U.S. Patent Application Publication No. 2006/0251919A1 discloses an EL device having OLEDs comprising an electroluminescent material layer, which comprises a mixture of at least two materials having different electron and hole transport capacities, and an electron transport layer comprising a triazine. Disclosed OLEDs may comprise an electron transport layer containing a triazine.
However, as discussed above, there remains a need for new film configurations containing new electroluminescent and charge transport compounds, and which have improved properties. These needs and others have been met by the following invention.